Nondestructive evaluation of uni- and biaxial strain-distributions in Si-on-insulator (SOI) structures is essential to accelerate research and development of next-generation-strained-Si-transistors. We investigate polarized Raman scattering from (001) SOI-microstructures with SiN-stress-liners. Raman intensities are analyzed as a function of the angle between -axis and polarization-directions of scattered-light. Interestingly, inactive Raman peaks in strain-free Si for scattered-light polarized along  and  directions become active in strained-Si, which is quantitatively explained by crystal-symmetry-change from cubic to orthorhombic or tetragonal structures. These findings enable precise evaluation of strain-distributions. Based on these results, selective-mapping of uni- and biaxial-strains in SOI-microstructures is demonstrated.